Kumchang-Ni is a nuclear reactor complex located on an island off the coast of the Northern Province of North Korea. The entire facility is heavily populated by numerous KPA Elites, and a few regular soldiers armed with RPGs. The most effective means of slipping past all of these defenses are by procuring an NK vehicle (Sungri Scout is a good choice) and disguising one's self as one of the North Korean forces, due to the total lack of KPA Officers in the entire area. Several alarms are scattered throughout the facility and if any of these are triggered, a continuous swarm of KPA troops will flood out of their barracks until the alarms are destroyed or deactivated. Also surrounding the complex is what appears to be a large hydroelectric plant of some sort as the base is surrounded by water and a very high, and thick, wall with open tunnels located at certain points (Most likely this is the reactor's coolant system).

Chul Kang, the Ace of Hearts, is holed up somewhere in Kumchang-Ni, when the player receives the mission to seek out the Ace, s/he is inserted into the facility under the cover of night, to covertly infiltrate the facility and verify Kang. However, once the player reaches the site where Kang is supposedly located in, it turns out Kang was aware of the mercenary's infiltration and set up an ambush, overloading the complex's nuclear reactor while he makes his getaway at a helipad on the far side of the base. The mercenary races through the entire facility, crossing a vast distance of catwalks with many Elite soldiers and RPG troops intercepting him/her, eventually reaching the helipad and verifying the Ace, and, as part of a bonus objective, discovers a videotape on Kang's person that contains extremely important information, before evacuating the facility as it detonates in a massive explosion.

The Elite soldiers stationed here are wearing an alternate "nuclear" outfit that looks like an ordinary NK Elite outfit only they are now wearing a gas mask similar to the Jack of Hearts, radioactive symbols on their shoulders, and numerous canisters around their waist.